/**
*
*/
package com.fkhwl.fkhserver.core.utils;
import java.awt.Image;
import java.awt.image.BufferedImage;
import java.io.File;
import java.io.FileInputStream;
import java.io.FileOutputStream;
import java.io.InputStream;
import javax.imageio.ImageIO;
import com.sun.image.codec.jpeg.JPEGCodec;
import com.sun.image.codec.jpeg.JPEGImageEncoder;
/**
* @ClassName: ThumbnailTools
* @Description: 缩略图生成工具
* @author
* @date 2014年9月25日 下午5:18:33
*/
public class ThumbnailTools {
private int fileSize;
private String inPath;
// 输入图路径
private String outPath;
// 输出图路径
private int width = 100;
// 默认输出图片宽
private int height = 100;
// 默认输出图片高
private String inFileName;
// 输入图文件名
private String outFileName;
// 输出图文件名
private boolean proportion =
true;
// 是否等比缩放标记(默认为等比缩放)
private String prefix = "thumbnail_"
;
public int getWidth() {
return width;
}
public void setWidth(
int width) {
this.width =
width;
}
public int getHeight() {
return height;
}
public void setHeight(
int height) {
this.height =
height;
}
public ThumbnailTools setSize(
int size){
this.width =
size;
this.height =
size;
return this;
}
public ThumbnailTools setSize(
int width,
int height){
this.width =
width;
this.height =
height;
return this;
}
public String getInPath() {
return inPath;
}
public void setInPath(String inPath) {
this.inPath =
inPath;
}
public String getOutPath() {
return outPath;
}
public void setOutPath(String outPath) {
this.outPath =
outPath;
}
public boolean isProportion() {
return proportion;
}
public void setProportion(
boolean proportion) {
this.proportion =
proportion;
}
public ThumbnailTools(String path){
this.inPath =
path;
this.outPath =
path;
}
public ThumbnailTools(String inPath, String outPath){
this.inPath =
inPath;
this.outPath =
outPath;
}
/**
* 生成缩略图
* @param fileName 文件名
* @return boolean
*/
public boolean generate(String fileName)
throws Exception{
this.generate(fileName,
null);
return Boolean.TRUE;
}
/**
* 生成缩略图
* @param fileName 文件名
* @param outFileName 输出文件名
* @return boolean
*/
public boolean generate(String fileName, String outFileName)
throws Exception{
File file =
new File(inPath+
fileName);
this.inFileName =
fileName;
this.outFileName =
null == outFileName ? prefix+
inFileName : outFileName;
this.execute(
new FileInputStream(file));
return Boolean.TRUE;
}
public boolean generate(InputStream inputStream, String outPath)
throws Exception{
this.execute(inputStream);
return Boolean.TRUE;
}
private void execute(InputStream inputStream)
throws Exception {
this.fileSize =
inputStream.available();
BufferedImage oldImage =
ImageIO.read(inputStream);
if (oldImage.getWidth() == -1
) {
System.out.println("Input image cant't read or format error."
);
return;
}
int newWidth;
int newHeight;
// 是否是等比缩放
if (
this.proportion ==
true) {
// 为等比缩放计算输出的图片宽度及高度
double rate1 = ((
double) oldImage.getWidth()) / (
double) width;
double rate2 = ((
double) oldImage.getHeight()) / (
double) height;
// 根据缩放比率大的进行缩放控制
double rate = rate1 > rate2 ?
rate1 : rate2;
newWidth = (
int) (((
double) oldImage.getWidth()) /
rate);
newHeight = (
int) (((
double) oldImage.getHeight()) /
rate);
} else {
newWidth = width;
// 输出的图片宽度
newHeight = height;
// 输出的图片高度
}
BufferedImage tag =
new BufferedImage((
int) newWidth, (
int) newHeight, BufferedImage.TYPE_INT_RGB);
// Image.SCALE_SMOOTH 的缩略算法 生成缩略图片的平滑度的 优先级比速度高 生成的图片质量比较好 但速度慢
tag.getGraphics().drawImage(oldImage.getScaledInstance(newWidth, newHeight, Image.SCALE_SMOOTH), 0, 0,
null);
String newFilePath = outPath+
outFileName;
File newFile =
new File(newFilePath);
FileOutputStream out =
new FileOutputStream(newFile);
// JPEGImageEncoder可适用于其他图片类型的转换
JPEGImageEncoder encoder =
JPEGCodec.createJPEGEncoder(out);
encoder.encode(tag);
inputStream.close();
out.close();
System.out.println(newFilePath+" ok, size: "+(fileSize/1024)+"kb to "+(newFile.length()/1024)+"kb"
);
}
public static void main(String[] args) {
try {
new ThumbnailTools("D:/").setSize(300, 200).generate("1.jpg", "2.jpg"
);
} catch (Exception e) {
e.printStackTrace();
}
}
}
大家在运行的时候或许会报错，因为该程序需要java两个jar包的支持
在Eclipse中处理图片，需要引入两个包： import com.sun.image.codec.jpeg.JPEGCodec; import com.sun.image.codec.jpeg.JPEGImageEncoder; 报错: Access restriction: The type JPEGImageEncoder is not accessible due to restriction on required library C:\Java\jre1.6.0_07\lib\rt.jar
此时解决办法：Eclipse默认把这些受访问限制的API设成了ERROR。只要把Windows-Preferences-Java-Complicer-Errors/Warnings里面的Deprecated and restricted API中的Forbidden references(access rules)选为Warning就可以编译通过。
转载于:https://www.cnblogs.com/plf112233/p/4154644.html
相关资源：java生成图片的缩略图
